Composite fountain blade construction for remote ink control system

ABSTRACT

An ink fountain blade assembly which includes a rigid backing member and a plurality of identical blade sections secured to the surface of the backing closely edge to edge and extending cantilever fashion to present a common substantially continuous film-forming edge for presentation to the surface of an associated fountain roller, one lateral edge of each of the blade sections being relieved along its cantilevered portion by an amount which is sufficient to permit freedom of adjusting movement toward and away from the roller but which is less than that which will leak a body of ink supported on the blade sections. Each blade section is chamfered in a rear corner position to provide distinctive visual indication, for assembly purposes of the edge which has been relieved.

United States Patent Easoz Oct. 24, 1972 [54] COMPOSITE FOUNTAIN BLADE2,837,024 6/1958 Dougan ..101/365 CONSTRUCTION FOR REMOTE INK CONTROLSYSTEM Primary Examiner-J. Reed Fisher 72 Inventor: Robert D. Easoz,Woodridge, n1. Bmnaugh at [73] Assignee: North American RockwellCorpora- ABSTRACT Pmsburgh, An ink fountain blade assembly whichincludes a rigid [22] Fil d; Sept 13, 1971 backing member and aplurality of identical blade sections secured to the surface of thebacking closely [21] Appl' 179585 edge to edge and extending cantileverfashion to present a common substantially continuous film-fenn- 52] us.Cl ..101/365 ing edge for Presentation to the Surfeee of en 51 Int. Cl...B41f31/04 sedated fountain Feller, one lateral edge of each of 5 Fieldf Search 01 5 5 363, 148 207 the blade sections being relieved along itscantilevered 0 7 08 57'"R671sflggxfi 'fif portion by an amount which issufficient to permit freedom of adjusting movement toward and away fromthe roller but which is less than that which will [56] References Cltedleak a body of ink supported on the blade sections.

UNITED STATES PATENTS Each blade section is chamfered in a rear cornerposition to provide distinctive visual indication, for as- 980,454 1/1911 11101118011 sembly p p of the g has been relieved 2,062,154 [1/1936Welk ..10l/365 6/1939 7 Claims, 4 Drawing Figures Baue ..101/365COMPOSITE FOUNTAIN BLADE CONSTRUCTION FOR REMOTE INK CONTROL SYSTEMWhile the forming of a film of ink from an ink body for printingpurposes may be accomplished in a number of different ways, by far themost popular procedure is to employ a fountain blade having an edgewhich can be controllably adjusted relative to a cooperating fountainroller to form a predetermined thickness of ink on the roller, the inkbeing lifted from the surface of the roller and conveyed to a plate onthe plate cylinder in the form of a thin continuous film by a series oftransfer rollers and form rollers. While the necessity for providing afilm of constant thickness is often emphasized, good quality printingrequires that different amounts of ink be fed to the plate on the platecylinder depending upon the need which exists at each point along theplate cylinder. Different amounts of ink are usually required in localareas across the width of the plate cylinder as determined by variationsin the image area to be printed. Since a fountain blade in a practicalthickness is relatively stiff, providing a series of adjusting screwsalong the film-forming edge does not permit an adequate differentialadjustment of ink feed in adjacent locations. To overcome this, effortshave been made in the past to provide a blade assembly consisting of anumber of independently adjustable sections each of which is subject toadjustment by its own adjusting screw. Faltus U.S. Pat. No. 1,574,474 isan example of the use of a segmented blade, but in this case thesections are moved backwardly and forwardly in the plane of the bladeassembly. Baue U.s. Pat No. 2,161,943 shows blade sections secured to arigid backing, and having provision for adjusting movement perpendicularto the plane of the blade assembly, but with the blades in contact edgeto edge. Experience has shown that such blades are not capable of trueindependent adjustment and that the blade sections bind upon oneanother. Adjustment of one blade not only affects the adjustment of theadjacent blades, but the binding effect is indeterminant so that a boundblade may release itself for no apparent reason during a printing runresulting in a sudden and unwanted change in the amount of ink beingfed.

Dougan U.S. pat No. 2,837,024 discloses a blade assembly having sectionswhich are relatively widely spaced and in which the blade has an overallflexible covering to prevent leakage between the sections. Such acomposite blade has not proved to be the answer to the problem since,for the sake of durability, it is necessary to employ rubber orrelatively stiff composition and in a thickness sufficiently great sothat adjustment tends to be transmitted from one section to the next todefeat independence of adjustment.

It is, accordingly, an object of the invention to provide a bladeassembly for an ink fountain which overcomes the problems which havebeen encountered in the prior art. That is, it is an object to provide ablade assembly which consists of a number of adjacent sections each ofwhich is controlled entirely independently of the others by a suitableadjusting screw, which avoids the binding of one blade section upon thenext as the adjustment is being made and in which, nevertheless, theblade sections are sufficiently closely spaced over their cantileveredportions as to contain a body of ink without leakage. It is a relatedobject to provide a blade assembly which consists of a series ofcompletely independently adjustable sections having clearance slotsbetween them but in which leakproof integrity is retained regardless ofthe degree of adjustment of any single blade section.

It is an object of the invention in another of its aspects to provide ablade assembly in which little or no care need be exercised incident tothe assembly of the individual blade sections upon a backing and inwhich mounting of the blade sections insures an accurately predeterminedamount of lateral clearance between the blade sections. Thus it is anobject to provide a composite blade assembly and assembling procedure inwhich clearance between the cantilevered portions of the blades may beobtained inexpensively and yet held to within extremely close andexacting limits.

Other objects and advantages of the invention will become apparent uponreading the attached detailed description and upon reference to thedrawings in which:

FIG. 1 is a sectional view of a blade assembly constructed in accordancewith the present invention cooperating with a fountain roller.

FIG. 2 is a fragmentary perspective showing one end of the fountain ofFIG. 1 but without the supporting bracket.

FIG. 3 is a plan view showing one end of the blade assembly and theadjacent fountain end wall.

FIG. 4 shows the profile of a single blade section.

While the invention has been described in connection with a preferredembodiment, it will be understood that I do not intend to limit theinvention to the particular embodiment shown but intend, on thecontrary, to cover the various alternative and equivalent arrangementsincluded within the spirit and scope of the appended claims.

Tuming now to the drawin there is shown at 10 an ink fountain for aprinting press having a pair of end plates 11 (only one of which isshown) and having a fountain roller 12 in contact with a body of ink 13.The fountain roller will be understood to be conventional, that is, itwill be understood to have a hard peripheral surface which is sealed atits ends with respect to the end plates, with provision for drivingintermittently or at a slow rate of speed.

Extending between the end plates 11 is a supporting bracket 15 which isarranged downwardly at an angle and which has, threaded into its frontedge, a series of adjusting screws, or keys, l6. Mounted upon the uppersurface 17 of the bracket is a blade assembly 20 consisting of bladestructure 21 secured to a rigid backing member 22. The latter has anupper surface 23 and a lower surface 24 which seats upon the bracket.The backing member is secured to the bracket by a series of registeringpins 25 and a series of screws 26, the screws being threaded intorespective tapped holes 27 in the backing plate.

In accordance with the present invention the blade 21 is of compositeconstruction being formed of a plurality of identical blade sections ofrectangular shape having shank portions arranged closely edge to edgealong the backing member and having cantilevered portions presentingtips alined with one another to produce a substantially continuousfilm-forming edge, one lateral edge of each cantilevered portion beingrelieved to a constant depth so that the section may undergo freeindependent movement for adjustment of ink film. The lateral edges ofeach blade section are machined precisely perpendicular to the plane ofthe assembly and the depth of the relief is limited to a value whichwill insure independent movement but will prevent leakage betweenadjacent blade sections in all conditions of relative adjustment.Moreover, the shank portion of each blade section is permanently markedto identify the relieved side thereby to facilitate assembly and toenable subsequent verification that no more than a single relief existsbetween any two adjacent blade edges. Thus, turning to the exemplaryembodiment shown in the drawing, the composite blade, indicated at 21,is shown to consist of a plurality of relatively narrow blade sections30.

Since adjacent blade sections are identical it will suffree to focusattention on a typical section as illustrated in FIG. 4. Here it will beseen that the blade 30 has a shank portion 31 having parallel lateraledges 33, 34 and a cantilevered portion 32 having parallel lateral edges35, 36 as well as a film-forming edge, or tip, 37. The lateral edge 36has a lateral relief 38 which extends roughly half the length of theblade section and which has a limited but precisely defined width whichis preferably 0.0005 inch. The edges 33, 35 are smoothly continuouswhile the relieved edge is formed of slightly offset portions 34, 36defining between them a step, or root, 39.

Because of the shallowness of the step 39 the edge having the relief ishard to identify by visual observation and, accordingly, to assistidentification, the relieved edge carries a telltale, non-symmetricalmarking, preferably in the form of a chamfer as indicated at 40. Thisfacilitates assembly since, if the chamfers on all of the blade sectionsare faced the same way, there will be no possibility that the relievedportions of adjacent blades will be coincident. In other words, byfacing the blades so that the chamfers are symmetrically oriented therewill be assurance that the slots between all of the cantileveredportions of adjacent blades will be precisely the same. Properorientation can be verified at any ume.

In accordance with one of the more detailed aspects of the presentinvention the depth of the relief is such that when the blades areassembled on the backing plate 22 with the lateral edges 33, 34 of eachof the blade sections clamped in intimate engagement from one bladesection to the next, the blades will be oriented perfectly parallel toprovide clearance between the cantilevered portions which are ofaccurately predetermined constant width, the clearance being at leastapproximately 0.0003 inch so that the sections may undergo free andindependent movement but less than about 0.0007 inch, thus providing aslot having a width dimension which is sufficiently small as to preventleakage of conventional commercial offset lithographic ink of normalviscosity between adjacent blade sections. It has been found that theviscosity of the standard commercial ofiset lithographic printing inksin common usage in sufficiently high so that there is little or notendency for the ink to leak or weep between the blade sections. Bycarefully machining all of the lateral edges, including that which formsthe relief, absolutely perpendicularly to the plane of the blades,leakage is avoided regardless of the condition of adjustment of theadjusting screws. Indeed, adhering to the preferred range of relief, nodifficulty has been experienced with ink drawn by capillary actionbetween the adjacent cantilevered sections of the blade. A sectionresponds promptly to minute changes in adjustment, both inwardly as anadjusting screw is screwed in and outwardly, with followup, when theadjusting screw is turned in the retract direction.

In carrying out the present invention the shank portions 31 of the bladesections 30 are secured to the backing member 22, not by riveting ormachine screws which might have a tendency to develop localized strainin the body of the blade, but by a chemical bonding agent or adhesivewhich is preferably of the thermosetting type. Thus in manufacturing thepresent blade assembly 20 the bonding agent is applied between the bladesections and the top surface 23 of the backing member. With the bladesclamped tightly edge to edge, bonding pressure is applied and maintainedover a heat cycle. A wide range of commercial adhesives of thethermosetting type are available and capable of face-bonding the metalsurfaces to produce a reliable and permanent joint. While selection of aparticular bonding agent does not form a part of the present inventionit is preferred to employ the material which is identified, simply byway of example, as Scotch Welding Tape No. LII-844050. Application ofthe bonding agent in tape form has the advantage that the bonded areamay be accurately and conveniently localized. In accordance with one ofthe detailed aspects of the present invention the backing plate is sodimensioned as to extend, in the direction of the fountain roller,beyond the line of relief indicated at 41 (FIG. 3) which connects theroots of the slots. Further in accordance with the invention the bondedarea is not extended all the way out to the edge 22a of the backingplate but only to a margin 42 which lies between the line of relief 41and the front edge of the plate. As a result the relieved portions ofeach blade section are partially bonded and not entirely cantilevered.

Further in accordance with the invention, the backing plate 22 isforeshortened in the longitudinal dimension so that the presented outeredges of the blade sections at the respective ends of the blade assemblyproject beyond the backing member. Accordingly, at assembly, the bladeassembly can be clamped and bonded precisely to the specified overalllateral dimension such that when the blade assembly is mounted to thebracket 15 the outer edges of the blade sections at the respective endsof the assembly will have the required close sliding fit with theparallel inwardly facing surfaces on the respective fountain end plates11.

In some applications, clamping screws 45 can be provided which penetratethe end plates and which engage registering longitudinally extendingtapped holes 46 in the backing member such that the end plates may bedrawn into intimate engagement with the presented edges of the bladeassembly.

It will be apparent that the present construction amply meets theobjects set forth above. Accurate machining of the individual bladesections 30, which are identical to one another, presents no problem andtheir manufacture may be largely automated. Application of the bondingagent and the assembling of the blade sections on the backing memberwith the chamfers 40 all faced the same way produces extremely narrowslots of constant width without exercise of special care or attention.Note that at assembly the shank portions 31 of the blade sections may beclamped as tightly as desired edge to edge without risk of narrowing theslots, i.e., without risk of contact or binding between the cantileveredend portions. Subsequent bonding is a simple matter of using aprescribed heat and curing cycle in accordance with recommendationsaccompanying the commercial bonding agent.

The supporting bracket which bridges the end walls of the fountain andupon which the backing member is supported, is tipped forwardly so thatthe blade sections in their normally relaxed state are spaced from thesurface of the fountain roller. Turning the adjusting screws 16associated with the individual tips of the blade sections causes thelatter to be shifted upwardly to establish a predetermined smallclearance with respect to the fountain roller, a clearance which may bereadily varied depending upon the ink feed requirements at local areasalong the entire length of the fountain roller. Because of the finiterelief which exists over the entire cantilevered portion of each of theblades, adjustment is truly independent and adjust ing one section hasno effect whatsoever upon adjustment of an adjacent section.

What is claimed is:

1. A blade assembly for a fountain in a printing press which comprises arigid backing member providing a flat mounting surface, a plurality ofblade sections of identical rectangular shape having shank portionsarranged closely edge to edge along the mounting surface and havingcantilevered portions which extend beyond the mounting surfacepresenting tips generally alined with one another to produce acontinuous film-forming edge, one lateral edge of each cantileveredportion being relieved to a constant depth of at least 0.0003 inch toform slots between the sections so that the sections may undergo freeindependent movement for adjustment of the ink film, the relief having amaximum depth of 0.0007 inch and the lateral edges of each blade sectionbeing precisely parallel to one another so as to prevent leakage betweenadjacent blade sections in all conditions of relative adjustment of thesections, the shank portion of each blade section beingnon-symmetrically marked for each visual identification of the relievededge thereby to facilitate assembly on the backing member withconsistent orientation to insure that no more than a single reliefexists between any two adjacent blade edges.

2. The combination as claimed in claim 1 in which the depth of therelief on each of the blades is substantially 0.0005 inch.

3. The combination as claimed in claim 1 in which the marking ispermanent and in the form of a chamfer on identical ones of the cornersof the shank portion of each blade section.

4. The combination as claimed in claim 1 in which the mounting surfaceon the backing member is extended beyond a line connecting the roots ofthe slots for partial support of the cantilevered portions.

5. The combination as claimed in claim 1 in which the blade sections areface-bonded to the mounting surface and in which the bonding agentextends beyond a line connecting the roots of the slots.

6. An ink fountain for a printing press comprising, in combination, aframe including side plates presenting opposed parallel surfaces, afountain roller having a surface extending from one side plate to theother, a rigid backing member providing a flat mounting surface spacedfrom the roller and angled downwardly withrespect to it, a plurality ofblade sections of identical rectangular shape having shank portionssecured closely edge to edge along the mounting surface and havingcantilevered portions which extend beyond the mounting surface in thedirection of the roller presenting tips generally alined with another toproduce a continuous film-forming edge, means including adjustmentscrews for positioning said cantilevered blade sections, one lateraledge of each cantilevered portion being relieved to a constant depth sothat when the blade sections are similarly oriented slots of equal widthare defined between them, the lateral edges of each blade section beingprecisely parallel to one another and the depth of the relief on each ofthe sections permitting free independent movement of the blade sectionsupon adjustment of the screws and precluding leakage of ink betweenadjacent blade sections in all conditions of relative adjustment of thesections, the blade assembly being dimensioned for snug fit between theend plates for containment of a body of ink above the blade assembly.

7. The combination as claimed in claim 6 in which the backing member islongitudinally foreshortened so that the presented lateral edges of theblade sections at the respective ends of the blade assembly projectbeyond the backing member and into close ink sealing engagement with theend plates, and threaded clamping means at each of the end plates fordrawing the end plates into intimate engagement with the presentededges.

1. A blade assembly for a fountain in a printing press which comprises arigid backing member providing a flat mounting surface, a plurality ofblade sections of identical rectangular shape having shank portionsarranged closely edge to edge along the mounting surface and havingcantilevered portions which extend beyond the mounting surfacepresenting tips generally alined with one another to produce acontinuous film-forming edge, one lateral edge of each cantileveredportion being relieved to a constant depth of at least 0.0003 inch toform slots between the sections so that the sections may undergo freeindependent movement for adjustment of the ink film, the relief having amaximum depth of 0.0007 inch and the lateral edges of each blade sectionbeing precisely parallel to one another so as to prevent leakage betweenadjacent blade sections in all conditions of relative adjustment of thesections, the shank portion of each blade section beingnon-symmetrically marked for each visual identification of the relievededge thereby to facilitate assembly on the backing member withconsistent orientation to insure that no more than a single reliefexists between any two adjacent blade edges.
 2. The combination asclaimed in claim 1 in which the depth of the relief on each of theblades is substantially 0.0005 inch.
 3. The combination as claimed inclaim 1 in which the marking is permanent and in the form of a chamferon identical ones of the corners of the shank portion of each bladesection.
 4. The combination as claimed in claim 1 in which the mountingsurface on the backing member is extended beyond a line connecting theroots of the slots for partial support of the cantilevered portions. 5.The combination as claimed in claim 1 in which the blade sections areface-bonded to the mounting surface and in which the bonding agentextends beyond a line connecting the roots of the slots.
 6. An inkfountain for a printing press comprising, in combination, a frameincluding side plates presenting opposed parallel surfaces, a fountainroller having a surface extending from one side plate to the other, arigid backing member providing a flat mounting surface spaced from theroller and angled downwardly with respect to it, a plurality of bladesections of identical rectangular shape having shank portions securedclosely edge to edge along the mounting surface and having cantileveredportions which extend beyond the mounting surface in the direction ofthe roller presenting tips generally alined with another to produce acontinuous film-forming edge, means including adjustment screws forpositioning said cantilevered blade sections, one lateral edge of eachcantilevered portion being relieved to a constant depth so that when theblade sections are similarly oriented slots of equal width are definedbetween them, the lateral edges of each blade section being preciselyparallel to one another and the depth of the relief on each of thesections permitting free independent movement of the blade sections uponadjustment of the screws and precluding leakage of ink between adjacentblade sections in all conditions of relative adjustment of the sections,the blade assembly being dimensioned for snug fit between the end platesfor containment of a body of ink above the blade assembly.
 7. Thecombination as claimed in claim 6 in which the backing member islongitudinally foreshortened so that the presented lateral edges of theblade sections at the respective ends of the blade assembly projectbeyond the backing member and into close ink sealing engagement with theend plates, and threaded clamping means at each of the end plates fordrawing the end plates into intimate engagement with the presenTededges.